Which of the following reacts with $2,4-DNP$ reagent to give an orange precipitate?

Which reagent is used to distinguish Acetophenone and Benzophenone?

$CH_3-CHO$ $\xrightarrow{HCN} (A)$ $\xrightarrow{H_3O^{+}} (B)$ $\xrightarrow{\Delta} (C)$ $\xrightarrow{LiAlH_4} (D)$ $\xrightarrow{HIO_4} HCHO + (E)$. Compound $(C)$ can show geometrical isomerism. Product $(E)$ of the reaction will be:

The major product $(Z)$ of the following chemical reaction is

Metaformaldehyde is:

Which of the following reagents can form a hydrazone with alkanone?